head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Pure Mechanics
Pioneering rhythm game where a rapping dog believes his way through button-cue raps.

Execution · Pure Mechanics
A one-button rhythm game where you defibrillate patients by pressing exactly on the seventh beat.
PaRappa the Rapper leans Execution (Pure Mechanics); Rhythm Doctor leans Execution (Pure Mechanics).
Rhythm Doctor leans a little harder on execution, though the gap is small.
PaRappa the Rapper
Hitting button cues on beat is the whole game
Rhythm Doctor
One-button timing to the seventh beat demands frame-tight precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
PaRappa the Rapper
No opponent; teachers follow set lines
Rhythm Doctor
No opponent; patterns are fully scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
PaRappa the Rapper
Songs are fixed sequences
Rhythm Doctor
Levels are fixed; only visual gimmicks obscure timing
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
PaRappa the Rapper
Freestyle scoring quirks for Cool rank
Rhythm Doctor
Learning each level's rhythm tricks is light routing
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.